How to Configure Jenkins with SSL Behind Nginx on Ubuntu 20.04

Jenkins is an open-source tool automation solution that enables the continuous delivery of software. It is used to set up the full software delivery pipeline. This allows developers to manage and control software delivery processes throughout the product’s lifecycle, allowing them to build, test, and reliably deploy their software.

Jenkins has an extendable architecture with a dynamic and active community. The programming language used is Java. In most cases, Jenkins operates as a self-contained Java servlet application. Java servlet containers like Apache Tomcat and GlassFish can also be used to run the program.

Organizations can use Jenkins to automate and speed up the software development process. Jenkins combines all development lifecycle stages, including build, document, test, package, stage, deploy, static analysis, and many others.

Plugins assist Jenkins in achieving Continuous Integration. DevOps stages can be integrated thanks to plugins. Installing the utility’s plugins is necessary to incorporate that tool. Git, Maven 2 projects, Amazon EC2, HTML publishers, etc. are a few examples.


How to install and use TCPflow (TCPDump alternative)

On Unix-like systems like Linux, TCPflow is a free, open-source, and potent command line utility for network traffic analysis. It records information sent or received across TCP connections and saves it in a file for subsequent examination in a way that makes protocol analysis and debugging possible.

Since it processes packets from the wire or a saved file, t is a program similar to tcpdump. It is compatible with the same potent filtering expressions as its sibling. The sole distinction is that tcpflow organizes all TCP packets into separate files (one for each direction of flow) and assembles each flow for later analysis.

Its feature set also includes a sophisticated plug-in system for reversing MIME encoding, decompressing HTTP connections that have been compressed, and calling external programs for post-processing, among other things.

Tcpflow has a wide range of applications, including understanding network packet flows, forensics, and disclosing the contents of HTTP connections.


How to Add a User to Sudoers in AlmaLinux or Rocky Linux

What is sudoers in Linux?

Have you ever wondered why it takes “sudo” or “su” to make system-wide changes in a Linux terminal? Su means “super user,” while sudo means “super user do.” With this command, you’re requesting root access and the status of a super user. If your name is not on the list, Linux checks a specific file to see if you are authorized to be given root access, much like a VIP CLUB. While you can still obtain root capabilities, you must log in as root to do so. This is not a very secure course of action. Reason: If you have root access, your system’s doors are wide open, making it vulnerable. The commands “sudo” and “su” permit you to run a specific program that you specify.

That individual file already has the maintenance user account configuration in certain distributions. You type:

command sudo

And enter your user account’s password, or

su root

And then, type the command after entering the root password. I’ve come to understand that not all distributions support this simple process, and you might need to manually add your username to the sudoers file. We just took the VIP list from the guard dozing off, and we’ll teach you how to add your name. (more…)

Crontab Basics Tutorial


A daemon’s name is Cron. Daemons are utility programs in Linux that operate in the background, monitoring and carrying out activities in response to triggering events and programmed schedules. Daemons can also be used to automate repetitive tasks.

The origin of the term “cron” can be traced back to the Greek word “Chronos,” which can be translated as “time.” Cron is a daemon that operates according to a set timetable or calendar, as this indicates.

A long-running piece of software known as the cron daemon is a system tool responsible for executing commands at specific dates and times. When using cron daemons, you can schedule computer activities as one-time events, occasional events, or as jobs that are scheduled repeatedly and on a regular basis.

Cron scheduling is useful for many businesses because it can automate repetitive operations, edit databases, data, or files, send bulk email messages, and conduct administrative tasks on a predetermined schedule.

The scheduling syntax that cron utilizes is also often used by software that does not run on operating systems. An example is Zuar’s Mitto data pipeline solution. Mitto can automate a wide range of processes by utilizing cron scheduling, including manipulating data within data warehouses, pulling data from other software, and many more.

The term ‘Cron Table’ can be abbreviated to ‘Crontab,’ a component of Cron. It is a file containing the cron schedule that needs to be executed and the commands used to automate operations and activities. When you make a new cron job, its information will be saved in the crontab file.
System administrators can only modify the system crontab file. However, many administrators are supported by Unix-like operating systems. Everybody can make a crontab file and add commands to it anytime.

Users may automate system upkeep, disk space monitoring, and backup scheduling with cron jobs. Cron jobs are ideal for servers and other machines that operate continuously because of their nature.

Cron jobs can be useful for web developers even though system administrators often utilize them.

As a website administrator, you could, for instance, set up three cron jobs: one to check for broken links every Monday at midnight, one to back up your site every day at midnight automatically, and one to delete the cache of your site every Friday at noon. (more…)

Backup and restore GPG keys on Linux


The issue of privacy is becoming more and more controversial. Users of Linux can encrypt files with public-key cryptography by using the gpg command. If you were to lose your encryption keys, this would be a disastrous situation. This is how you may support their claims.

OpenPGP and GNU Privacy Guard

One benefit of electronic files over paper hard copies is the ability to encrypt them so that only authorized users may access them. It won’t matter if they end up in the wrong hands. The contents of the files are only accessible to you and the intended recipient.


How to Install and use Monit on Linux


In UNIX/Linux-based systems, Monit is a free, open-source tool that automatically manages processes, files, directories, checksums, permissions, filesystems, and services like Apache, Nginx, MySQL, FTP, SSH, SMTP, and others. It also gives system administrators excellent and practical monitoring functionality.

A native HTTP(S) web server or the command line interface can be used to immediately view the system status and setup procedures via the monit’s user-friendly web interfaces web server, such as Apache or Nginx, must be installed on your system in order to access and view the Monit web interface. (more…)

Monitor Linux CPU temperature using s-ui

What is s-tui?

“s-tui” is a terminal utility that runs GNU/Linux and is made to stress test and monitor our CPU. It is a program that graphically displays the frequency of CPU temperature utilization and power consumption without needing an X server. It was created by Alex Manuskin and is written in Python.

An effective way to determine whether a cooling system is working well or whether we have a stable overclock is to run a stress test on a computer. S-tui makes it simple to identify overheating when you see a decrease in frequency. Additionally, it will display any signs of decreased performance.

We can use the tool over SSH because it operates in the terminal. This is helpful if you enjoy using the terminal or for monitoring servers or small PCs like Raspberry Pi.

S-tui does not display precise information about the active processes in the system, which is one drawback of this tool. Just imagine the overall scene. S-tui won’t be of assistance if we’re searching for a tool that provides us with details about specific processes or allows us to manage these processes.

Install s-tui on Ubuntu using the PPA

The installer can also be downloaded and installed for Ubuntu systems using pip or a PPA. We merely need to launch a terminal (Ctrl + Alt + T) and enter the following commands to install s-tui from the PPA:

sudo add-apt-repository ppa:amanusk/python-s-tui && sudo apt update && sudo apt install python-s-tui

To start the program, we need to type “s-tui” in the terminal.

By adding stress, we can expand the program’s alternatives. This package allows us to run the stress test. Although installing this program is not required, it performs excellently. To accomplish this, using the terminal, we type:

sudo apt install stress

Archlinux users:

Use the Pacman command to install the pip package for Archlinux users.

sudo pacman -S python-pip stress

Fedora users:

sudo dnf install python-pip stress

For CentOS/RHEL users:

sudo yum install python-pip stress

For openSUSE users:

sudo zypper install python-pip stress

Stress can be used to highlight the CPU. All the graphs will advance to their maximum values if we choose this mode of operation.
Finally, use the pip command below to install the s-tui utility on Linux:

For Python 2.x:

sudo pip install s-tui

For Python 3.x:

sudo pip3 install s-tui

Getting to S-TUI

The article’s introduction stated as much. To obtain all the information from your system, root privilege is required. To start s-tui, simply enter the following command.

sudo s-tui

By default, it activates hardware monitoring and chooses the “Stress” option to put your system through a stress test.
Go to the help page to see alternative possibilities.

s-tui --help

5 Best Practices to Prevent SSH Brute-Force Login Attacks in Linux


Typically, SSH-enabled servers make for easy targets for brute-force attacks. The ongoing development further increases the risk of intrusion by hackers of new software tools and bots for automating brute-force attacks.

This manual will look at strategies to protect your SSH servers from brute-force attacks on Linux distributions based on RHEL and Debian derivatives.

1. Disable SSH Password Authentication and Enable SSH-Key Authentication

Username/password authentication is the standard authentication technique for SSH. But as we have seen, brute-force attacks can be used to target password authentication systems. Implementing key-based SSH authentication, in which authentication is made possible via public and private SSH key pairs, is advised to be safe. While the public key is copied to the server, the client’s private key stays on their computer.

During SSH key authentication, the server verifies whether the client PC has the private key. A shell session is created, or the command supplied to the remote server is executed if the check is successful. You may find detailed instructions for configuring SSH key-based authentication on our website. (more…)

How to Analyze and Optimize MySQL performance


MySQL is an open-source relational database that many users prefer to use in their daily operations because of the diversity of storage engines it supports, its flexibility and high performance, robust data security, cost-effectiveness, ease of maintenance, and reliability.

Why should MySQL performance be measured and monitored?

Ensuring smooth and effective database performance is one of the most important features of any organization or company, large or small. Thus, in some cases, having a complete understanding of database uptime or load is crucial and should be monitored frequently.

As a result, numerous monitoring tools are available on the market to track, analyze, and measure performance, as well as examine potential difficulties. They help you optimize queries and visualize database metrics, collect statistics, and present the performance status so that you can understand the influence on overall performance and potential issues that need to be troubleshot.
The following advantages may emerge from optimizing database performance: (more…)

Setup Secure FTP server on Linux using VSFTPD


Have you ever worked away from home and realized that you left a critical document on your computer? The optimal method is to utilize an FTP server such as Very Secure FTP Daemon (VSFTPD).
You can install and configure an FTP server using VSFTPD on your Linux server by following the steps in this guide. With this server, you can safely transfer files to other computers.

Continue reading, and you’ll never have to worry about your files being held hostage on your home computer again!
The File Transfer Protocol, sometimes known as FTP, is a standard network protocol that sends and receives data to and from remote networks. Linux users have access to various open-source FTP servers to choose from. PureFTPd, ProFTPD, and vsftpd are the ones that have the most notoriety and are utilized the most frequently. We will install vsftpd (Very Secure FTP Daemon), a dependable, secure, and quick FTP server. In addition, we will demonstrate how to configure the server so that users can only access their home directories and the entire transmission is encrypted using SSL/TLS.

Although FTP is a highly used protocol, you should consider using SCP or SFTP instead if you want to transfer data in a more protected and expedient manner.
In this blog, we will use Ubuntu and similar Debian base distribution; however, any other Linux distribution should also work. (more…)